build: bump azure pipelines python to 3.9

Author: mrava87

azure-pipelines.yml

@@ -26,7 +26,7 @@ jobs:
 #   steps:
 #   - task: UsePythonVersion@0
 #     inputs:
-#       versionSpec: '3.7'
+#       versionSpec: '3.9'
 #       architecture: 'x64'
 #
 #   - script: |
@@ -55,7 +55,7 @@ jobs:
   steps:
   - task: UsePythonVersion@0
     inputs:
-      versionSpec: '3.8'
+      versionSpec: '3.9'
       architecture: 'x64'
 
   - script: |
@@ -84,7 +84,7 @@ jobs:
   steps:
   - task: UsePythonVersion@0
     inputs:
-      versionSpec: '3.8'
+      versionSpec: '3.9'
       architecture: 'x64'
 
   - script: |